Need Help 1994 Gmc Suburban, 5.7 L 350 4x4

i got a smoking problem, lol not health wise but with the truck
sucks.

At Cold Start it blows blueish white smoke heavly, and if i try to put the truck
in drive or Reverse it bogs out and dies. But if i leave it in Neutral and rev for about 1 to 3 mins and blows
smoke even more but i can then drop it in gear and drive. but once truck starts driveing theres no more smoke
and it runs fine sounds fine. But once i shut off the truck it restarts the proccess. blows smoke like no tommarow, have to rev to
get it clear so i can put it in drive or reverse. Any Ideas what it is ?

you might have shot valve guide seals,remember a motor pulls the most vacuum at idle,quick test,at end of commute,shut down quickly,start up in morn.get in and go,try for a day or two,see if you get less smoke.back to high vacuum at idle,it is just sucking oil past the seals cause it is the quickest route to cylinder